The ultrastructure of grafted neonatal ovaries.

An ovary from a syngenic newborn donor was grafted into each ear of 9 ovariectomized and 3 intact adult female DA strain rats. Cycling resumed in ovariectomized animals after an average interval of 24 days. The average duration of the resumed cycles was 6 days. The histology and ultrastructure of grafted ovaries are compared with those of normal ones. Thecal cells became luteinized in grafted ovaries. The ultrastructure of interstitial tissue cells from grafted ovaries reflects increased specialization for steroidogenesis.